Geoscience frontiers最新文献

{"title":"The catalytic effect of silver on acidic ferric-sulfate leaching of chalcopyrite: A microscopic cyclic reaction","authors":"Barbara Etschmann ,&nbsp;Luis Verdugo ,&nbsp;Alexander Kalintsev ,&nbsp;Maryam Olamide Abdus-Salam ,&nbsp;Rahul Ram ,&nbsp;Luke Vollert ,&nbsp;John O’Callaghan ,&nbsp;Yang Liu ,&nbsp;Timothy Williams ,&nbsp;Paul Guagliardo ,&nbsp;Joël Brugger","doi":"10.1016/j.gsf.2025.102119","DOIUrl":"10.1016/j.gsf.2025.102119","url":null,"abstract":"<div><div>Copper extraction from chalcopyrite is challenging, because acid dissolution is slow, occurring incongruently via a complex three-step reaction mechanism. Silver has been known to catalyse copper extraction from chalcopyrite since the 1970's; yet the mechanism remains controversial. Microcharacterisation of experimental products obtained under optimal leaching conditions (50–150 μm chalcopyrite grains in ferric/ferrous-sulfate solution with a redox potential around 500 mV vs. Ag/AgCl, approximately 1ppm Ag; [Ag] 6.4 × 10⁻⁶ mol/L; 70 °C; 4 days) highlights the heterogeneity of the reaction: µm-thick layers of a porous copper-sulfide with variable composition formed both in cracks within, and on the surface of the chalcopyrite grains. There is no evidence for formation of Ag-rich phases (Ag₂S_(s), Ag⁰_(s)). The fundamental three-step reaction mechanism remains the same with or without added silver; silver merely accelerates the initial dissolution step.</div><div>An integrated model for the catalytic effect of silver is proposed that incorporates recent advances in the reactivity of sulfide minerals. The initial reaction follows a ‘<em>Fluid-Induced Solid State Diffusion Mechanism</em>’, where diffusion of Fe in the chalcopyrite lattice is driven towards the surface by its rapid removal into solution, resulting in a Fe-deficient surface layer. The large Ag⁺ ion, relative to Cu⁺/Fe³⁺, diffuses into this Fe-deficient surface layer and accelerates chalcopyrite dissolution in the subsequent step, whereby chalcopyrite is replaced by copper sulfides via an <em>interface coupled dissolution reprecipitation reaction</em> as a consequence of the sulfide-rich micro-environment at the mineral surface. Effective Ag⁺ recycling is key to the catalytic effect of silver, and occurs as a result of the strong affinity of Ag⁺ for bisulfide ligands accumulating at the surface of dissolving chalcopyrite.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 5","pages":"Article 102119"},"PeriodicalIF":8.9,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A dynamic DRASTIC-based approach for multi-hazard groundwater vulnerability mapping","authors":"Muhammad Umar Akbar ,&nbsp;Ali Mirchi ,&nbsp;Arfan Arshad ,&nbsp;Abubakarr Mansaray ,&nbsp;Ahsan Saif Ullah ,&nbsp;Kaveh Madani","doi":"10.1016/j.gsf.2025.102117","DOIUrl":"10.1016/j.gsf.2025.102117","url":null,"abstract":"<div><div>This study advances the DRASTIC groundwater vulnerability assessment framework by integrating a multi-hazard groundwater index (MHGI) to account for the dynamic impacts of diverse anthropogenic activities and natural factors on both groundwater quality and quantity. Incorporating factors such as population growth, agricultural practices, and groundwater extraction enhances the framework’s ability to capture multi-dimensional, spatiotemporal changes in groundwater vulnerability. Additional improvements include refined weighting and rating scales for thematic layers based on available observational data, and the inclusion of distributed recharge. We demonstrate the practical utility of this dynamic DRASTIC-based framework through its application to the agro-urban regions of the Irrigated Indus Basin, a major groundwater-dependent agricultural area in South Asia. Results indicate that between 2005 and 2020, 54% of the study area became highly vulnerable to pollution. The MHGI revealed a 13% decline in potential groundwater storage and a 25% increase in groundwater-stressed zones, driven primarily by population growth and intensive agriculture. Groundwater vulnerability based on both groundwater quality and quantity dimensions showed a 19% decline in areas of low to very low vulnerability and a 6% reduction in medium vulnerability zones by 2020. Sensitivity analyses indicated that groundwater vulnerability in the region is most influenced by groundwater recharge (42%) and renewable groundwater stress (38%). Validation with in-situ data yielded area under the curve values of 0.71 for groundwater quality vulnerability and 0.63 for MHGI. The framework provides valuable insights to guide sustainable groundwater management, safeguarding both environmental integrity and human well-being.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 5","pages":"Article 102117"},"PeriodicalIF":8.9,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A study of PM2.5 transport pathways in China from 2000 to 2021 with a novel spatiotemporal correlation method","authors":"Yiming Liu ,&nbsp;Huadong Guo ,&nbsp;Lu Zhang ,&nbsp;Dong Liang ,&nbsp;Qi Zhu ,&nbsp;Zhuoran Lv ,&nbsp;Xinyu Dou ,&nbsp;Xiaobing Du","doi":"10.1016/j.gsf.2025.102116","DOIUrl":"10.1016/j.gsf.2025.102116","url":null,"abstract":"<div><div>In the context of urbanization, air pollution has emerged as a significant environmental challenge. A thorough understanding of their transport pathways, especially at a national scale, is essential for environmental protection and policy-making. However, it remains partially elusive due to the constraints of available data and analytical methods. This study proposed a data-driven spatiotemporal correlation analysis method employing the Dynamic Time Warping (DTW). We represented the first comprehensive attempt to chart the long-term and nationwide transport pathways of PM_2.5 utilizing an extensive dataset spanning from 2000 to 2021 across China, which is crucial for understanding long-term air pollution trends. Compared with traditional chemical transport models (CTMs), this data-driven method can generate transport pathways of PM_2.5 without requiring extensive meteorological or emission data, and suggesting fundamentally consistent spatial distribution and trends. Our analysis reveals that China’s transport pathways are notably pronounced in the Northwest (34% of the total pathways in China), Southwest (22%), and North (21%) regions, with less significant pathways in the Northeast (10%) region and isolated occurrences elsewhere. Additionally, a notable decrease in the number of China’s PM_2.5 transport pathways, similar to annual average concentrations, was observed after 2013, aligning with stricter environmental regulations. Furthermore, we have demonstrated the feasibility of applying our method to the transport pathways of other gaseous pollutants. The approach is effective in detecting and quantifying air pollutants’ transport pathways, even in regions like the Northwest with limited monitoring infrastructure, which may aid in environmental decision-making. The study will notably improve the current understanding of air pollutants’ transport process, providing a new perspective for studying the large-scale spatiotemporal correlations.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 5","pages":"Article 102116"},"PeriodicalIF":8.9,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracing carbonate diagenesis and hydrothermal activity during the opening of the Central South Atlantic: Insights from the Santos Basin (Brazil)","authors":"Igor Figueiredo ,&nbsp;Cristiano Lana ,&nbsp;Fernando F. Alkmim ,&nbsp;Marco A. Silva ,&nbsp;Maria Eugênia S. Souza ,&nbsp;Dorval C. Dias-Filho ,&nbsp;Eveline E. Zambonato ,&nbsp;Katia R.N. Mendonça","doi":"10.1016/j.gsf.2025.102115","DOIUrl":"10.1016/j.gsf.2025.102115","url":null,"abstract":"<div><div>The opening of the Central South Atlantic and the consequent formation of the eastern Brazilian continental margin was marked by a complex history of mafic magmatism, carbonate sedimentation, and deposition of a thick salt layer. The carbonates underlying the salt layer (pre-salt carbonates) were formed in restricted lacustrine basins. Here, the timing and fluid sources of deposition, diagenetic, and hydrothermal alterations of the pre-salt carbonate rocks are defined through <em>in-situ</em> U-Pb dating, ⁸⁷Sr/⁸⁶Sr, and trace element analyses of samples from the Santos Basin. The very alkaline nature of the Aptian lake(s) produced characteristically unique and widely distributed carbonate rocks such as Mg-clays with calcite spherulite and calcite crystal shrub limestones transitioning laterally and vertically into travertines formed by hydrothermal pulses during basin evolution. Hydrothermalism caused extensive replacement, dissolution, and calcite cementation. REE+Y PAAS-normalised patterns and ⁸⁷Sr/⁸⁶Sr ratios indicate that deposition/eo-diagenesis of the primary carbonates occurred in a lacustrine environment primarily controlled by evaporation, pH, and continental water source, with 2%–10% hydrothermal fluid input. Trace elements and Sr-isotope of travertines and burial diagenetic phases show that they are produced from a<!--> <!-->hot mixture of mafic/mantle-derived fluids and dissolution/alteration of older carbonate formations. U-Pb dating indicates that carbonate deposition occurred between 124.8 ± 2.6 Ma and 120.0 ± 1.6 Ma, earlier than previously proposed, followed closely by the circulation of hydrothermal fluids. Replacement and cementation ages range from 120.5 ± 2.4 Ma to 80.4 ± 2.4 Ma.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 5","pages":"Article 102115"},"PeriodicalIF":8.5,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction and early warning analysis of reservoir bank slopes based on anti-sliding stability evolution","authors":"Yaoru Liu ,&nbsp;Chenfeng Gao ,&nbsp;Wenyu Zhuang ,&nbsp;Chengyao Wei ,&nbsp;Zhenlian Qi ,&nbsp;Kai Zhang ,&nbsp;Shaokang Hou","doi":"10.1016/j.gsf.2025.102113","DOIUrl":"10.1016/j.gsf.2025.102113","url":null,"abstract":"<div><div>The stability of reservoir bank slopes during the impoundment period has become a critical issue in the construction and operation of large-scale hydropower projects. A predictive and early warning method for reservoir bank slopes is proposed, based on slip resistance stability evolution analysis. Using a refined three-dimensional numerical calculation model of the bank slope, the creep damage model is employed for simulation and analysis, enabling the derivation of stress field and strain field evolution from bank slope excavation to the long-term impoundment period. Subsequently, for the stress field of the bank slope at any given moment, the safety factors of the sliding blocks are determined by using the multigrid method and vector sum method. Accordingly, the evolutionary law of the sliding safety factor for the bank slope can be derived. By integrating the long-term stability evolution trend of the slope with specific engineering practices, the safety factors for graded warning can be determined. Based on the time correspondence, the graded warning moment and the deformation warning index for slope measurement points can be determined. In this study, the proposed method is applied to the left bank slope of the Jinping I Hydropower Station. The results indicate that from excavation to June 2022, the left bank slope exhibits a strong correlation with excavation elevation and the number of reservoir water cycles. The initial, maximum, and minimum safety factors are 2.01, 3.07, and 1.58, respectively. The deep fracture SL_44-1 serves as the primary stress-bearing slip surface of the left bank slope, while the safety margin of the fault f_42-9 and lamprophyre X is slightly insufficient. Based on the long-term stability evolution trend of the slope and in accordance with relevant standards, the safety factors for graded warning indicators—<em>K_w</em>₁, <em>K_w</em>₂, <em>K_w</em>₃, and <em>K_w</em>₄—are determined as 1.350, 1.325, 1.300, and 1.275, respectively. Correspondingly, the estimated warning times are 12/30/2066, 12/30/2084, and 12/30/2120. Accordingly, the deformation graded warning indexes for slope measurement points are established.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 5","pages":"Article 102113"},"PeriodicalIF":8.5,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stepwise aridification of the Late Paleozoic North China Craton","authors":"Weikai Xu ,&nbsp;Yong Li ,&nbsp;Thomas J. Algeo ,&nbsp;Zhuangsen Wang ,&nbsp;Xiaofang He","doi":"10.1016/j.gsf.2025.102114","DOIUrl":"10.1016/j.gsf.2025.102114","url":null,"abstract":"<div><div>The Late Paleozoic marked Earth’s most recent icehouse–greenhouse transition, providing valuable insights into future climate and environmental changes. Although the aridification of the North China Craton (NCC) during the Late Paleozoic is well established, its pattern and causes remain unclear. Here, we identify four aridification intervals from the late Gzhelian to Lopingian by analyzing continuous records of elemental climate proxies (MgO/CaO, Sr/Cu), a volcanism proxy (Hg/TOC), and spore–pollen assemblages. Interval I (∼303–295 Ma), during which the NCC was located at low paleolatitudes, was characterized by humid conditions and a predominance of ferns, associated with weak volcanism. Interval II (∼295–286 Ma) was subhumid, with increasing gymnosperm presence, and significant climate fluctuations linked to volcanism. CO₂ emissions from the Tarim LIP and Panjal Traps drove aridification from the late Asselian to late Artinskian, contributing to the decline of the Late Paleozoic Ice Age. As a result, aridification in the NCC lagged behind that of Pangea. Interval III (∼286–280.98 Ma) marked the transition to subarid conditions and the onset of dominance by gymnosperms, associated with a rapid northward drift of the NCC and an increase in atmospheric <em>ρ</em>CO₂. Interval IV (∼259.51–251.902 Ma), separated from the underlying Interval III by a major regional unconformity (∼280.98–259.51), coincided with global aridification and intensified volcanism. These findings highlight the significant influences of both tectonic plate motion and volcanism on the climate evolution of the NCC, with shifts in the dominant controlling factors through time. This study provides new insights into the distinct trajectories of global and regional climate dynamics.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 5","pages":"Article 102114"},"PeriodicalIF":8.5,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geological, structural, and temporal framework of hematite-rich IOCG mineralization at La Farola deposit in the Candelaria-Punta del Cobre district, Chile","authors":"N.M. Seymour ,&nbsp;I.del Real ,&nbsp;A. Canales ,&nbsp;H. Stein ,&nbsp;G. Yang ,&nbsp;J. Camacho","doi":"10.1016/j.gsf.2025.102112","DOIUrl":"10.1016/j.gsf.2025.102112","url":null,"abstract":"<div><div>Iron oxide-copper–gold (IOCG) deposits encompass a diverse set of mineralization styles, leading to outstanding questions about how different alteration facies are related across a single ore-producing system and the overarching mechanisms of ore genesis. This study investigates the age and characteristics of mineralization at the La Farola deposit, a hematite-dominated IOCG deposit located at the southern margin of the Candelaria-Punta del Cobre IOCG district of northern Chile. Two lithologically-controlled ore bodies occur along the WSW-ENE striking, ∼18° NNW-dipping contact between the Lower Cretaceous Chañarcillo Group and Punta del Cobre Formation. Syn-mineralization N-S to NNW-SSE striking sinistral strike-slip faults likely acted as fluid pathways. Distinct mineral assemblages include an early Na-Ca assemblage (albite-scapolite) overprinted by skarnoid garnet with minor pyroxene, Ca-Fe (magnetite-actinolite), and K-Fe (magnetite-k-feldspar-biotite and minor sulfides) assemblages. The main sulfide mineralization (chalcopyrite-pyrite with minor bornite) is associated with specular hematite-white mica-K-feldspar-calcite and overprints all previous assemblages. The presence of hematite as the dominant Fe-oxide phase associated with Cu mineralization is characteristic of lower-temperature IOCG deposits, and may be a result of La Farola’s stratigraphic position &lt;700 m higher than other deposits in the district. New U-Pb ages of 115.7 ± 1.2 Ma for garnet and Re-Os ages of ∼113–114 Ma for sulfides indicate mineralization occurred within a 3-million-year timeframe. These findings confirm hematite-dominant mineralization at La Farola was coeval with IOCG mineralization across the district. This research contributes to understanding IOCG systems and their formation mechanisms, highlighting the control local geological structures and alteration processes has on the diversity of mineralization types associated with a single IOCG system.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 5","pages":"Article 102112"},"PeriodicalIF":8.5,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical softening of lunar olivine probed via nanoindentation and high-pressure X-ray diffraction measurements","authors":"P. Grèbol-Tomàs ,&nbsp;J. Ibáñez-Insa ,&nbsp;J.M. Trigo-Rodríguez ,&nbsp;E. Peña-Asensio ,&nbsp;R. Oliva ,&nbsp;D. Díaz-Anichtchenko ,&nbsp;P. Botella ,&nbsp;J. Sánchez-Martín ,&nbsp;R. Turnbull ,&nbsp;D. Errandonea ,&nbsp;A. Liang ,&nbsp;C. Popescu ,&nbsp;J. Sort","doi":"10.1016/j.gsf.2025.102110","DOIUrl":"10.1016/j.gsf.2025.102110","url":null,"abstract":"<div><div>The mechanical properties of minerals in planetary materials are not only interesting from a fundamental point of view but also critical to the development of future space missions. Here we present nanoindentation experiments to evaluate the hardness and reduced elastic modulus of olivine, (Mg, Fe)₂SiO₄, in meteorite NWA 12008, a lunar basalt. Our experiments suggest that the olivine grains in this lunaite are softer and more elastic than their terrestrial counterparts. Also, we have performed synchrotron-based high-pressure X-ray diffraction (HP-XRD) measurements to probe the compressibility properties of olivine in this meteorite and, for comparison purposes, of three ordinary chondrites. The HP-XRD results suggest that the axial compressibility of the orthorhombic <em>b</em> lattice parameter of olivine relative to terrestrial olivine is higher in NWA 12008 and also in the highly-shocked Chelyabinsk meteorite. The origin of the observed differences is discussed. A simple model combining the results of both our nanoindentation and HP-XRD measurements allows us to describe the contribution of macroscopic and chemical-bond related effects, both of which are necessary to reproduce the observed elastic modulus softening. Such joint analysis of the mechanical and elastic properties of meteorites and returned samples opens up a new avenue for characterizing these highly interesting materials.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 5","pages":"Article 102110"},"PeriodicalIF":8.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144723557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Palynofloral and geochemical evidence for Permian-Triassic transition from Talcher Coalfield, Son-Mahanadi Basin, India: Insights into age, palaeovegetation, palaeoclimate and palaeowildfire","authors":"Srikanta Murthy ,&nbsp;Deveshwar P. Mishra ,&nbsp;Dieter Uhl ,&nbsp;Anju Saxena ,&nbsp;Vikram P. Singh ,&nbsp;Runcie P. Mathews ,&nbsp;Anurag Kumar ,&nbsp;Bindhyachal Pandey","doi":"10.1016/j.gsf.2025.102086","DOIUrl":"10.1016/j.gsf.2025.102086","url":null,"abstract":"<div><div>The Permian-Triassic (P/T) transition is marked by the most severe mass-extinction event of the Phanerozoic. Although much is known about this event in the marine realm, there are many open questions regarding what happened during this period to many continental biota. In the case of plants, a drastic mass-extinction event has even been negated by some authors. To add about the knowledge on continental biota in India during this crucial time period, the present study analysed the palynology, palynofacies, organic geochemistry (biomarkers), stable isotopes, and charcoal within the subsurface Gondwana deposits of the Kamthi Formation (late Permian-early Triassic) from core TTB-7 from the Tribida block, located in the Talcher Coalfield of the Mahanadi Basin, India.</div><div>The primary objectives are to validate the age of the strata, ascertain the palaeodepositional setting of the palaeomire, and propose palaeobotanical evidence regarding the occurrence of wildfires within this stratigraphic succession and changes in floral content across the P/T transition. The palynological study proposes two palynoassemblage zones, <em>Densipollenites magnicorpus</em> and <em>Klausipollenites schaubergeri,</em> suggesting a latest Permian (Lopingian) and early Triassic (Induan?) age for the studied succession, respectively. The age is also inferred based on correlation with coeval assemblages from India and other Gondwana continents. The palynoassemblages reveal the dominance of Glossopteridales and Coniferales along with Filicales, Lycopsidales, Equisetales, Cordaitales and Peltaspermales. The relatively higher values of the carbon preference index and terrigenous/aquatic ratio also suggest higher plant input. However, a bimodal <em>n</em>-alkane distribution pattern suggests the contribution of terrigenous and microbial sources. Although the occurrences of long-chain alkanes indicate input of higher plants, the low <em>P</em>_wax values (&lt;0.26) suggest relatively less contribution. The <em>P</em>_aqvalues (≅1) and amorphous organic matter (av. 33.24%) suggest a significant macrophyte input in the studied samples, pointing to the occurrence of moderate aquatic conditions in the basin.</div><div>Furthermore, the distribution of hopanoids and the content of degraded organic matter (av. 29.96%) reflect the bacterial degradation of organic matter. Also, the <em>δ</em>¹³C values of the studied section varied from −31.2‰ to −21.8‰. A large carbon isotopic offset of 9.4‰ across the P/T transition, Pr/Ph ratio (0.3–1.3) and shift in the distribution pattern of palynofacies components is indicating a significant change in climatic conditions. Moreover, the presence of macroscopic charcoal fragments of gymnospermous affinity with pre-charring colonization by fungi provides evidence for wildfire occurring during the Lopingian (Late Permian) in this basin.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 4","pages":"Article 102086"},"PeriodicalIF":8.5,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144570350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Orbital to millennial scale dust activity and humidity interaction in Central Asia during the last glacial period","authors":"Haoru Wei ,&nbsp;Yougui Song ,&nbsp;Shugang Kang ,&nbsp;Mingyu Zhang ,&nbsp;Mengping Xie ,&nbsp;Yanping Wang ,&nbsp;Li Han ,&nbsp;Shukhrat Shukurov ,&nbsp;Nosir Shukurov ,&nbsp;Fakhriddin Fayziev","doi":"10.1016/j.gsf.2025.102099","DOIUrl":"10.1016/j.gsf.2025.102099","url":null,"abstract":"<div><div>The factors controlling dust activity and humidity in Central Asia and their relationships remain controversial, partly due to a lack of high-resolution geological records for the mid-to-late last glaciation. In this study, we established an optically stimulated luminescence chronology for the QSHA profile in the Yili Basin, a region influenced by westerlies. Grain size and trace element data were used as paleoclimatic indicators. We investigated the relationships among Central Asian dust activity, humidity, and westerlies strength on orbital to millennial scale from 37.4 ka to 11.6 ka. Our study reveals that, on orbital timescales, humidity is positively correlated with westerlies strength which controlled by precession. Dust activity is controlled by Siberian High which was regulated by Northern Hemisphere high-latitude temperature. Their responses to low-latitude and high-latitude forcing mechanisms respectively and present an opposite relationship. On millennial timescales, humidity and westerlies strength are positively correlated. During Marine Isotope Stage (MIS) 2, humidity and dust activity show synchronous fluctuations, while during MIS 3, they exhibit an inverse relationship. Westerlies strength regulated humidity, which subsequently controlled glacial activity in the Tianshan Mountains, influencing dust activity in Central Asia. Additionally, the QSHA profile recorded seven Dansgaard-Oeschger (D-O) events on millennial timescales, indicating a potential link between Central Asian dust activity and high-latitude temperature variations in the Northern Hemisphere. Our findings provide new insights into dust and humidity interaction during the last glaciation periods in Central Asia and contribute to understanding global dust and hydrological cycles.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 4","pages":"Article 102099"},"PeriodicalIF":8.5,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144570136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}